mile

In the English-speaking world, 16th – 21st century and the Sudan , 20th century¹, a unit of distance = 5280 feet = 1760 yards = 8 furlongs, approximately 1.609 344 kilometers. Often referred to as the statute mile, from its having been defined in a statute of Elizabeth I (1592-93) which forbade building within 3 miles of the gates of London.

Although as early as 1607 legal authorities like John Cowell regarded the 5280-foot mile as the one intended in contracts and statutes, it did not in fact become the legal mile throughout the United Kingdom until the passage of the Act establishing the
imperial system of weights and measures in 1824.
Scotland, however, adopted the 1760-yard mile in 1685.²

In the 16th century and before miles other than the statute mile were certainly in use in Great Britain (see old English mile, below). Those miles were gradually superseded largely through government use of the 5280-foot mile. The Letter Office and later postal services relied on the statute mile. The postal act of 1660, for example, paid contractors carrying letters 3 pence per 5280-foot mile for each horse. Roads improved by the Turnpike Acts had milestones placed at 5280-foot intervals. Such measures accustomed people to thinking of a mile as 5280 feet.

2. An Act for a Standard of Miles, James VII (of Scotland, James II of the United Kingdom), 1685, Parl. I. Cap. 44.

Origin of the mile

The word “mile” comes from the Latin word for “thousand”,
from the phrase mille passus, literally
“thousand paces”. This distance was also known as a milliarium, literally
“milestone.” Below is a drawing of the insciption on a Roman milestone set
up in 276 ce near the village of Castor in Cambridgeshire. We know the date because most of the words on the stone are the full name of the emperor Florianus, who had a very short reign.

Drawing by R. G. Collingwood. Reproduced from A History of the County of Huntingdon, Volume 1 (London, 1926), p. 235. Image provided by the Victoria County History, University of London. See RIB.

The bottom line, “M.P. I.”, means mille passus one. During the Roman occupation of Britain (57 bce—450 ce), the mille passus must have been a familiar unit, at least along the Roman roads, and the word found its way into many local languages, including Irish, Cornish and Breton. The Roman pes was shorter than the current English foot, and a well-accepted guess at the length of the mille passus in Roman Britain is about 1,479.5 meters, about 90% of a statute mile. The Anglo-Saxons knew the mille passus, at least in literature, as the Þúsend stæppan, the thousand steps.

Each passus consisted of five pes, the Roman foot, so the mille passus was 5,000 pes. It was divided into 8 stadia, each of 625 pes. The Saxons also seem to have retained a 5,000-foot mile (their mil), but the Saxon foot was even shorter than the Roman one, closer to the size of a real human foot. The Saxon mil was probably about 1,257 meters, about 0.78 statute miles.

The question then becomes how the mile in England grew from 5,000 feet to 5,280 feet.

Why 5280 feet?

A table of equivalents for a system of units can reveal a great deal about the
system’s history. Compare the table of English units of length with, say, the table of units of liquid capacity. The conversion factors for the capacity units are whole numbers like 2 or powers of two. But key conversion factors in the table of English lengths are very strange numbers, such as 5½ yards or 16½ feet to the perch, and 5280 feet to the mile. Such numbers usually indicate that unrelated, pre-existing systems of units have been stuck together to form a new system. That is the case with the English units of length.

The yard began as a unit based on the human body. Perhaps you have measured cloth, or
rope, or wire, or anything long, by pinching a point between thumb and forefinger, extending your arm,and catching the point that touches your nose with the other hand. (In the 19th century Native Americans insisted that cloth they bought at a certain trading post be measured this way. They knew the trader could change marks on his yardstick, but not the distance from his nose to his thumb).

The perch, also called the rod or pole, was a Germanic unit arising from plowing technology. Physically the perch was a long stick used to guide the oxen and mark the width of furrows.

The furlong, the length of a furrow, was the distance a team of oxen could plow before needing a breather. It was 40 perches long, a ratio also found in continental Europe. Though there were many different perches, the matching furlong was always 40 times the length of the perch.

An acre was 4 perches wide and 1 furlong long. Thus the length of the perch and
of the furlong became built into the layout of fields.

The uses of the yard – measuring cloth, for example – and the uses of the
perch – measuring agricultural land – had nothing in common. There was no need
to know how many yards long a field was, and no reason to speak of “perches of
cloth.” But trade and governance require a system of measures whose correctness
can be verified, with clear relationships between the units. The easiest way to
achieve this is to choose one base unit for a property like length, define that unit with a physical standard,
and then define all other units in terms of the base unit. For English units of length, the
physical standard was an iron prototype of the yard. From at least about 1350 all English units of length, except the mile, were defined in terms of the prototype of the yard. Around 1600 the mile was added to the list.
But first, the perch.

Defining the perch in terms of the yard

In England the most common perch was one that was probably brought to the island by migrants from German-speaking areas. It was probably originally an even 16 Rhineland Fuss long, a length which survived into modern times in German-speaking Europe as the Ruthe. The English foot was shorter than the Rhineland Fuss; 16 Rhineland Fuss are about equal to 16½ English feet, so the closest acceptable approximation of the length of the field unit in cloth units, was 16½ feet, or 5½ yards. A statute of about 1350 firmly coupled the perch and yard. Notice the repeated insistence on the “Iron Yard of our Lord the King.” By fixing the length of the perch 16½ feet, the statute implicitly also defined the length of the furlong as 660 feet, since it was generally = 40 perches.

Statutum de Admensuratione Terre.

And Be it Remembered, That the Iron Yard of our Lord the King, containeth three Feet and no more. And a Foot ought to contain Twelve Inches, by the right measure of this Yard measured; to wit, The Thirty-sixth Part of this Yard rightly measured maketh one Inch, neither more nor less. And Five Yards and a half make one Perch, that is Sixteen Feet and a half, measured by the aforesaid Iron Yard of our Lord the King.

Thus the perch, a unit of land measurement, was patched into the system of
inch, foot and yard. It then remained to fit the mile, the unit of itinerant distance, into the system.

The mile was used by people walking or riding from one town to another. It had nothing to do with plowing or land area, but a lot to do with paces, or steps. The existing itinerant measures were in terms of steps, and even as late as the 18th century people actually counted the steps between towns. How did the Roman and Saxon round number, 1000 paces (or 5000 feet), get changed to 5280 feet?

About a century after the “Iron Yard” statute quoted above, a monk in Canterbury wrote¹

Notice that the century-old yard-based definition of the perch has taken hold; the author mentions the King's standard. But attempting to describe the mile in terms of the existing legally-defined units leads the monk to a correct but unworkable conversion factor (7½ furlongs 3 perches and 2 hands, which adds up to exactly 5000 feet).

Experience with the Roman mille passus had accustomed the English to the idea that a mile was subdivided into 8 parts. In Latin, those parts were stades. In those days, laws, legal proceedings, deeds, grants of land and other official documents were kept in Latin. “Mille” in Latin naturally became “mile” in English. The nearest equivalent in Latin to the English “furlong”, however, was the “stade” (625 pes). The educated knew that the Roman mille passus contained 8 stadia, and continually translating “furlongs” as stadia planted the idea that an English mile contained 8 furlongs.²

To get 8 furlongs in a mile, either the furlong had to be made 625 feet (5000-foot mile ÷ 8), or the mile had to be made
5280 feet(660-foot furlong × 8 ).

The length of the furlong, the basis of the acre, was not adjustable. The acceptance of a 16½ foot perch, instead of an even 16, demonstrated that. It was a fact on the ground on which the ruling classes' rents and revenues, the landholdings of farmers, and even the sizes of city lots, depended. A modest change in the mile, however, would have no great impact. The 8-furlong, 5,280-foot mile apparently appeared early in the 16th century. Late in that century Elizabeth I legalized it, in effect abolishing, at least around London, the 5,000-foot mile.

1. Joseph Brigstocke Sheppard, ed.Certa Mensura Cartuariensis.
Second Report on Historical Manuscripts belonging to the Dean and Chapter of Canterbury.
Appendix Pt. 1, page 325 of
Great Britain. Royal Commission on Historical Manuscripts.Eighth Report of the Royal Commission on Historical Manuscripts. Report and Appendix.—(Part I.)
London: H.M.S.O., 1881.

Augustus De Morgan called attention to this source in 1839 in his article “League” in the Penny Cyclopaedia, vol. 13, page 376. However, the transcription in De Morgan's article differs considerably from that in the Eighth Report.

sources

1

¶ The Fourme and the Mesur to mete Land by.

The lengith of a barly corne iij. tymes make an ynche, soo that the
barly growe in comon soyle not to leuene too mych compostid, and xij.
ynches make a fote and iij. fote make a yarde and v. quatirs of the yarde
make an elle, v. fote make a pace, C. xxv.
pace make a furlong, and viij. furlong make an English myle, and xvi. furlong make a Frensh leuge, V. yardis di. make a perche in Londo to mete lande by, and that perch is xvi. fote di. longe. In dyuers odur placis in this lande they mete grounde by
pollis gaddis and roddis som be of xviij. foote som of xx. fote and som
xxi. fote in lengith, but of what lengith soo euer they be C.lx. perches make
an akir, for as a mark of English monei conteyneth an C. lx. pence soo euery
akir lande conteyneth C. lx. perchies, and as a noble conteyneth lxxx. pense
soo half an aker lade conteyneth Ixxx. perchis, etc., and as the half a noble
conteyneth xl. d'. soo a roede lande coteyneth xl. perchi etc., and a perche
of grounde shal coteyngne I lengith of the perche euery wey i the maner
of a cheker soo y it be as loge as brode.

¶ Xvi fote and half makith a perch as is aboue said, that is v. yardis and half, vi. C. foote bv fife score to the C. makith a furlog, that is xxxviij. perchis sauf ij. fote,
viij. furlong make an English myle that is v. M. fote,
and so iij. C. and iij. perchis also an English myle.

The length of a barleycorn three times makes an inch (provided the barley grew in common soil, not too light nor too much
fertilized),
and 12 inches make a foot and 3 feet make a yard and 5 quarters of the yard make an ell. Five feet make a pace, 125 paces make a furlong, 8 furlongs make an English mile,
and 16 furlongs make a French lieue. Five and a half yards make a perch in London to measure land by, and that perch is 16½ feet long. In various other places in this land they measure ground by poles, gads and rods; some are 18 feet, some 20 feet and some 21 feet in length, but of whatsoever length they be, 160 [square] perches make an acre, for as a mark of English money contains 160 pence so every acre of land contains 160 [square] perches, and as a noble contains 80 pence so half an acre of land contains 80 [square] perches, etc., and as half a noble contains 40 pence, so a rood of land contains 40 [square] perches, etc. A [square] perch of ground shall contain the length of a perch in both directions, in the manner of a square, so it is as long as broad.

Sixteen and a half feet make a perch, as is said above, that is 5½ yards. Six hundred feet (counting a hundred as five score) makes a furlong, that is, 38 perches less 2 feet. Eight furlongs make an English mile, that is,
five thousand feet, and so 303 perchs are also an English mile.

The Customs of London, otherwise called Arnold’s Chronicle.
London: Printed for F. C. and J. Rivington; T. Payne; etc. , 1811.
Page 173.
The first edition appeared in Antwerp around 1502.

This quotation from very early in the sixteenth century
illustrates the 5000-foot mile and the 8-furlong mile, as well as the confusion at that time regarding the mile. The mile is first described in terms of paces, as 8 furlongs each of 125 paces, each pace of 5 feet, which is a 5000-foot mile and a 625-foot furlong. Six hundred twenty-five is the number of pes in a Roman stade.

The second paragraph describes the mile in terms of furlongs. It first says the furlong is 600 feet, making a 4800-foot mile, which is very close to the length of the Roman mille passus. But a furlong 38 perches less 2 feet long would be (38 × 16½ feet=627 feet, less 2 is) 625 feet, again making a 5000-foot mile. Three hundred three 16½-foot perches makes a 4999.5-foot mile, indistinguishable from 5000.

2

And that a Myle shalbe reckoned and taken in this manner and noe
otherwise, That is to saye, a Myle to conteyne Eight Furlongs, and everie Furlonge
to conteyne Fortie Luggs or Poles, and every Lugg or Pole to conteyne Sixtene Foote and
Halfe.

Mile (milliare) is a quantitie of a thousand paces, otherwise
described to containe eight furlongs, and euery furlong to conteine forty lugs
or poles, and euery lugge or pole to containe 16. foote and a halfe. anno 35.
El. cap 6.

John Cowell.The Interpreter: or Booke containing the Signification of Words: Wherein
is set forth the true meaning of all, or the most part of such Words and Termes,
as are mentioned in the Lawe Writers, or Statutes of this... etc.
Cambridge: John Legate, 1607.

Note that this is actually two definitions, separated by "otherwise described":
a mile of 5000 feet (1000 paces × 5 feet) and a mile of 5280 feet (16½ × 40). Useful in a law dictionary, since
a court of law might have to interpret the word in very old or very new
documents.

3

V. And it shall and may be lawfull to and for such Post Master
Generall and his Deputy and Deputyes to aske demand take and receive of every
person that he or they shall furnish and provide with Horses Furniture and Guide
to ride post in any of the Post roads as aforesaid Three pence of English money
for each Horses hire or postage for every English mile and Foure pence for the
Guide for every Stage.

...and that all Measures of Length shall be taken in Parts or Multiples, or certain Proportions of the Standard Yard; and that One-third Part of the said Standard Yard shall be a Foot, and the Twelfth Part of such Foot shall be an Inch; and that the Pole or Perch in Length shall contain Five such Yards and a Half, the Furlong Two hundred and twenty such Yards, and the Mile One thousand seven hundred and sixty such Yards.

5 George IV. Cap 74. sec 1. (17 June 1824)
In imperial measure, the mile is defined in terms of the prototype Standard Yard.

2

In England, one or more units of itinerant distance, often called the
old English mile, which was longer than the statute mile. That such a unit was in use as late as the 18th century is abundantly obvious from surviving maps and itineraries (see Close, Evans, Grundy, Petrie below; itineraries provide lists of points on a journey with the distances between them). The distances between English cities given in guidebooks as late as the 17th century use a mile which is probably around 1.3 statute miles.

The Roman mille passus is discussed above. When the Romans conquered
Gaul, they found another unit of itinerant distance in use there, which they
called the leuga. It was so widespread that, during the reign of the
Emperor Trajan (8 – 117 ce),
the Romans standardized it, using it as the interval between “mile” stones on the roads of Gaul.

In the Gallic system, 1 leuga = 12 quarentenae, and 1 quarentena = 40 perticae (the Latin names). These are units derived from ploughing, and correspond in concept but not magnitude to the English mile, furlong and perch.

The period in which this mile was in use is not clear, perhaps 14th – 17th century, although some think it may be no older than the statute mile.

sources

1

As for the old British mile that includeth 1500 paces English, it
shall not greatly need to make any discourse of it, and so much the less sith it is
yet in use and not forgotten among the Welsh men, as Leland has noted in his
Commentaries of Britain.

Seebohm, in Customary Acres, says the
above sentence occurs
in the first, 1577 edition of William Harrison's
Description of the Iland of Britain. It does not occur in the second edition
(1587).

Fifteen hundred paces would make the "old British mile" 7500 feet. That the ordinary English mile in Harrison's text is
an 8-furlong mile
is clear from the following passage:

Betweene the part of Holland also, which lieth neere the mouth
of the Rhene and this our Iland, are 900 furlongs, as Sosimus saith ; and besides him,
diuers other writers, which being conuerted into English miles, doo yeeld
112. and foure od furlongs...

William Harrison.An Historicall Description of the Iland of Britaine; with a Briefe Rehersall
of the Nature and Qualities of the People of England, and such commodities as
are to be found in the Same. Book I, chapter 2, page 5.
prefixed to:Holinshed's Chronicles of England, Scotland and Ireland. Vol. I. England.
London: Printed for J. Johnson; F. C. and J. Rivington; etc. 1807.

3

It remaines now that according to my owne experience, I should speake something of the divers kindes of miles. And in generall, this my opinion hath respect to the difficult or easie passages of the way, since even in England, the miles seeme, and indeed are more short, neere London, where the waies are faire and plaine, and frequently inhabited, as they seeme, and indeed are more long and tedious, through the desart places of the North, over mountaines, and through uninhabited and difficult passages.

The Romans of old held a thousand paces for a mile, and such are the miles of Italie.

A common English mile makes one & a halfe Italian, but towards the North, & in some particular places of England, the miles are longer, among which the Kentish mile (being a Southerne County) is proverbially held to be extraordinarily long.

The Irish miles among the English, and the Irish-English are answerable to the English; howsoever for the solitary and disinhabited wayes, and many foards often overflowed, they are more troublesome to passe.

In like sort the miles of Scotland, answere to the Northerne miles of England, save that the frequent climing of mountaines, and the unbeaten waies, make them seeme longer, and indeed require more time for the passage.

Fynes Moryson.An Itinerary containing his ten yeeres travell through the twelve dominions of Germany, Bohmerland, Sweitzerland, Netherland, Denmarke, Poland, Italy, Turky, France, England, Scotland & Ireland.
Glasgow: James MacLehose and Sons, 1907.
Part I, Book III, Chapter 6.
Pages 162-163 of this edition. The first edition was published in 1617, but the travels took place between 1591 and 1603.

The Italian mile, like the Roman, is 1000 paces, so if “a
common English mile” = 1½ Italian miles, the English mile would be
1500 paces.

4

So that in a measured Mile, there are 320 Poles, or 1760
yards, or 5280 feet, or 63360 inches, or 190080 barly-corns. But the miles
commonly accounted from one place to another are more, unlesse within 20 miles
round off London.